1. Field of the Invention
The present invention is related to a lamp assembly, and in particular, related to a Christmas lamp assembly comprising a plurality of lamp bulbs and a plurality of lamp holders integrally molded of synthetic resin in a water-proof manner.
2. Description of the Prior Art
It has been known from Taiwan Utility Model Patent No. 298295 as to an improvement of the Christmas lamp assembly, in which , as shown in FIGS. 1 through 3, the lamp assembly unit generally comprises a lamp bulb 1 having two metal wires 11 and 11 extending from the bottom thereof, a core 2 in the form of a hollow body opening to the top and having two through holes 21 and 21 at the bottom thereof through which the wires 11 and 11 may be inserted to the outside, a lamp holder 3 also in the form of a hollow body for receiving the core 2 at the upper portion thereof and being provided with an insertion hole 31, and two electric wires 4 and 4 having respectively two terminals 41 and 41 for being inserted through the insertion 31 to electrically connect the metal wires 11 and 11 of the lamp bulb 1, wherein the insertion hole 31 has cross sections 311 and 312 corresponding to the terminals 41 and 41 of the electric wires 4 and 4, the lamp holder 3 is provided with a flange 32 at the top thereof, an extension piece 22 extends downward from the bottom of the core 2 and has curved faces 221 and 222 respectively matching with the cross sections 311 and 312 thereby pinching two electric wires 4 and 4 upon engaging with the insertion hole 31 from above, and a peripheral groove 23 is arranged at the top of the core 2 so as to engage the flange 32 of the lamp holder 3 to prevent water from penetrating into the lamp holder 3 and ensure its engagement with the core 2.
In addition, there is disclosed another related improvement of lamp assembly in Taiwan Utility Model Patent No. 334102, in which, as shown in FIGS. 4 through 7, the lamp assembly comprises a core 2 having two protruded pieces 25 and 25 at the bottom thereof and a hollow portion 24 therein for engaging a lamp bulb 1 by inserting two wires 11 and 11 of the lamp bulb 1 through two bores 21 and 21 of the protruded pieces 25 and 25 and attaching them 11 and 11 to the outsides of the protruded pieces, a lamp holder 3 having two U-shaped engagement pieces 35 and 35 for engaging two protruded pieces 25 and 25 of the core 2, wherein two edges 36 and 36 disposed at the tops of the engagement pieces 35 and 35 and two hooks 37 and 37 disposed at the bottoms of the engagement pieces 35 and 35 may secure two terminals 41 and 41 of the electric wires 4 and 4 upon insertion of the wires 4 and 4 into the lamp holder from under, two convex pieces 38 and 38 being disposed at the lower portions of the engagement pieces 35 and 35, an insertion body 6 with a pair of curved grooves 61 and 61 respectively at both opposite sides corresponding to the positions of the convex pieces 38 and 38, wherein the curved grooves 61 and 61 may accommodate the electric wires 4 and 4 while engaging the insertion body 6 with the convex pieces 38 and 38, thereby reliably connecting the wires 4 and 4 in a water-proof way.
The inconvenience met in the above first-mentioned patent resides in that the electric wires 11 and 11 tend to deflect improperly and thus fail to electrically connect with the metal terminals 41 and 41, normally in the form of flat plates, since the wires 11 and 11 have to extend through the holes 21 and 21 of the core 2 and accurately fold left- or right-wise for desirable connection with the terminals 41 and 41, as shown in FIGS. 1 to 3. Accordingly, the lamp bulb 1 in question will not emit light. Further, the lamp holder 3 is generally made of opaque plastic, through which the above improper situation may not be watched until a real test is conducted. Thereafter, the failed connection must be replaced with a new one and, therefore, the yield as well as productivity thereof are considerably decreased.
Further, as shown in FIG. 3, the assembling sequence of the lamp assembly starts from the insertion of the bulb envelope 1 into the opening 24 of the core, which constitute a lamp bulb, and is succeeded by the insertion of the lamp bulb into the lamp holder 3. Since the bulb envelope is generally made of glass by blow molding, its outer profile may not appear constant in the circumference. As a result, there is always clearance existing between the bulb envelope 1 and the opening 24, through which water may easily penetrate into the lamp bulb from the outside, and thus causes problems of rusting corrosion or short circuit.
Moreover, the engagements between the lamp holder 3 and the electric wires 4 and between the extension piece 22 and the electric wires 4 and 4 may not be perfect to prevent water from penetrating into the clearance therebetween, and once more causes problems of rusting corrosion or short circuit.
In spite of the advantages claimed above, the inconvenience met in the above second-mentioned patent resides in that the bulb envelope 1, core 2, and lamp holder 3 arc separately made for later assembling together in a way similar to the first-mentioned patent. Especially, as shown in FIG. 7, the terminals 41 and 41 of the electric wires 4 and 4 are in the form of metal plates similarly thereto, the problems of bad electric connection, rusting corrosion and short circuit resulting from current leakage are also inevitable. Further, the insertion body 6 is additionally provided to prevent water from penetrating into the inside of the lamp holder 3, and thus increases the cost of parts and assembly.
The present invention is directed to solving the above drawbacks in the prior art. With the lamp bulb and the lamp holder according to the present invention, the former may be easily inserted into the latter for desirable electric connection with excellent water-proof ability, which may efficiently prevent water of raindrop or sludge from penetrating the inside of either of them and thus solve the problems of current leakage or short circuit in the above-mentioned prior arts.